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Finding the Fourth Proportional to 76.51, 105.57 and 72.97

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Solution

The fourth proportional to 76.51, 105.57 and 72.97 is: 100.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.51 : 105.57 = 72.97 : x
  2. Step 2: Convert to fraction form
    76.51/105.57 = 72.97/x
  3. Step 3: Cross multiply
    76.51x = 105.57 × 72.97
  4. Step 4: Simplify right side
    76.51x = 7,703.44
  5. Step 5: Solve for x
    x = 7,703.44/76.51
  6. Step 6: Final answer
    x = 100.69

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.